The roots of x2=18x−77 are.
x2=18x−77
x2−18x+77=0
x2−(11+7)x+77=0
x2−11x−7x+77=0
x(x−11)−7(x−11)=0
(x−11)(x−7)=0
x−11=0 x=11 and x−7=0 x=7
so value of x is 11 and 7